A continuous Class‐EF power amplifier based on the general continuous mode design theory

Abstract

SummaryContinuous mode provides better bandwidth performance and constant efficiency by offering greater design flexibility in fundamental and harmonics. However, this mode is mainly applicable to limited classes of power amplifiers (PAs) (such as Class‐F, Class‐J, and their derived types). In view of this problem, this paper proposes a general design theory for high‐efficiency broadband continuous PAs, which can easily extend any waveform of PAs to obtain the continuous impedance space. In theoretical analysis, first, the high‐efficiency equations are analyzed from the perspective of frequency domain. Furthermore, combining time domain constraints, a general continuous mode analysis and solution theory is presented. The theory is applied to the bandwidth expansion of Class‐EF PAs, resulting in a new continuous Class‐EF (C‐EF) mode that maintains constant efficiency while offering greater broadband design freedom. The proposed theory is verified by fabricating a C‐EF PA using GaN HEMT CGH40010F, which demonstrated output power (Pout) ranging from 39.5 to 41.2 dBm and drain efficiency (DE) of 69.5% to 79.2% in the frequency range of 2.5–3.6 GHz.